Tack-centering guide for tack-driving machines



No Model.) I

' D. B. NYE. TACK OENTBRING GUIDE FOR TACK DRIVING MACHINES.No."513,820.

Patented Jan. 30, 1894.

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Unrran STATES PATENT rrrce.

DAVID B. NYE, OF CAMBRIDGE, ASSIGNOR TO THE BOSTON LASTING MACHINECOMPANY, OF BOSTON, MASSACHUSETTS.

TACK-CENTERING GUIDE FOR TACK-DRIVING MACHINES.

SPECIFIGA'IION forming part of Letters Patent N0. 513,820, dated January30, 1894.

Application filed October 9,1893. Serial No. 487-613. (No model.) i

To all whom, it may concern.-

Be it known that I, DAVID B.NYE, of Oambridge, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Tack-Centering Guides for Tack-Driving Machines,of which the following is a specification.

This invention relates to an improvement on the split or elastic guidetube set forth in Letters Patent No. 464,200, dated December 1, 1891.Said guide tube is a tubular cone frustum of sheet-metal split orslotted from its smaller end' partly to its larger end to form a seriesof tongues, the larger end being left whole to serve as a tubular necksupporting said tongues. The tube is formed to receive and hold a tackin the path of a driver, the smaller end of the tube being normally ofless diameter than the head of the tack and adapted by its slottedconstruction to be expanded by the force exerted on the tack by thedriver, so that the tongues yield or are sprung outwardly, permittingthe tack to pass through the smaller end of the tube, the frictionalresistance exerted by the tongues on the periphery of the tack headcausing the head to be closely seated on the acting face of the driverand its shank to stand in line with the driver while being driven.Heretofore said tube has been circular in cross section throughout itsentire length, the tongues being therefore arched or concavo-convex incross section at all points. This form interferes materially with theresistance of the tongues, and in fact stiffens the same and resists theflexure to which they are subjected, so that they buckle when bent, theresult being that in some cases the continued flexure of the tonguescauses them to crack and break, thus necessitating the stoppage of themachine while a new tube is being applied.

My invention has for its object to obviate the above-mentionedobjection, and to this end it consists in a guide tube of the characterabove described having its tongues transversely flattened to increasetheir resilience, so that they can yieldor be sprung outwardly withoutthat buckling action which takes place when the tongues are arched incross section.

In the accompanying drawings forming a part of this specification-Figure1 represents a View of the blank from which myimproved guide tube ismade. Fig. 2 represents said blank after it has been slotted to form thetongues. Fig. 3 represents a perspective view showing the partly formedtube. Fig. 4 represents a perspective view showing the tube more nearlycompleted. Fig. 5 represents. a perspective view showing the completedtube. Fig. 6 represents a longitudinal section of the tube. Figs. 7, 8,and 9 represent respectively a section on line 7,7; 8,8; and 9, 9, Fig.6. Fig. 10 represents a longitudinal section showing the tube in itsexternal shield. Fig. 11 represents a section similar to Fig.'10,showing the driver ejecting a tack from the tube. Figs. 12 and 13 showenlarged side elevations of the improved guide-tube.

The same letters and numerals of reference indicate the same parts inall of the figures.

In the drawings or represents the tack centering guide which is composedof a conical tube of thin sheet metal, the tube being split or slottedfrom its smaller end partly to its larger end to form tapering tongues2, 2, 2. The unslotted portion of the tube constitutes a tubular neck 3,which supports the tongues and has an outwardly projecting flange 4adapted to be engaged with the parts B and O of the exterior tube, allas shown in the above mentioned Patent No. 464,200.

In carrying out my invention I simply fiatten each tongue 2transversely, so that each tongue instead of being arched in crosssection throughout its entire length, is fiat in cross section for asufficient part of its length to enable it to be flexed or sprung freelyto the extent required in ejecting the nail,without injury. I prefer toretain the arched form at the lower ends of the tongues, as shown inFig.9, this form enabling the-tongues to closely fit the periphery ofthe tack head, and thus insure the centering action described in saidpatent, the tongues being flattened between their lower ends and theneck 3.

In making the tube I prefer to take a flat blank of the form shown inFig.1, and slot the same as shown in Fig. 2. I then bend the blank asshown in Fig. 3 nearly into a completetube, and then flatten the desiredportions of the tongues by pressure suitably applied, the lower part ofthe neck being indented as shown at 5, 5, said indentations belng at theupperends of the flattened surfaces 2. A tack centering guide,consisting of a 20 tapering tube of sheet metal slotted longiof thetongues. This operation closes the tube by bringing together the edgesof the blank above the slots, and by also bringing together the edges ofthe slots. The flange 4 is then formed, thus completing the tube whichnow presents the appearance shown in Figs. 5, 6, 10 and 11.

I claim--- 1. A tack centering guide, consisting of a tapering tube ofsheet metal slotted longitudinally from the smaller end partly to thelarger end to form a series of tongues, integral with the body or largerportion of the tube said tongues being transversely flattened, wherebytheir resilience and durability are increased, as set forth.

tudinally from the smaller end partly to the larger end to form a seriesof tongues, said tongues being arched or curved in cross section attheir free ends, so that said ends approximately fit the periphery of atack head, and flattened transversely above their free ends, wherebytheresilience and durability of said tongues are increased, as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 29th day of September, A. D.1893.

DAVID B. NYE.

YVitnesses:

M. W. JACKSON, A. D. HARRISON.

